This invention relates generally to gas distribution systems and more particularly concerns valves used to temporarily connect external gas sources to operational customer gas lines.
The basic concept of a gas line override valve is explained in my U.S. Pat. No. 5,178,188 which teaches the use of a meter bypass swivel connector in the replacement of natural gas meters. In that application, a quick disconnect coupler 91 is snugly attached in a hole provided in a sleeve in the operational gas line. The coupler has a bias mechanism which prevents flow of gas through the coupler under normal conditions. Pressure from an external source on the biasing means opens the coupler to permit flow of gas from the external source into the sleeve. While this arrangement works effectively, the gas flow rate from the external source into the gas lines is limited by the biased coupler.
In another application of override valves, gas companies generally insert a regulator in the aboveground gas company line connecting the gas meter to the underground gas company feeder system. The pressure in the gas company's line is generally 50 to 60 psi and the regulator reduces the pressure on the customer side of the regulator to 9.2 inches of water column up to 2 pound systems. It is now becoming common practice for a gas company to insert a pressure excess flow valve with a manual reset in the underground line. This valve will close to cut off the underground line flow and protect the 9.2 inch water column side of the system if an increase in pressure exceeds the capacity of the 9.2 inch water column. However, once the underground excess flow valve has been operated, accessing the buried manual reset is a very expensive problem.
It is, therefore, an object of this invention to provide a gas line override valve having a quick disconnect coupler which maximizes input gas flow through the coupler into the operational gas lines. Another object of this invention is to provide a gas line override valve connectable above ground between the operational gas line regulator and the underground feeder to the system. It is also an object of this invention to provide a gas line override valve connectable in the high pressure side of an operational gas line capable of feeding gas at pressures sufficient to overcome the input pressures to the excess flow valve and thus reset the manual reset of the excess flow valve. A further object of this invention is to provide a gas line override valve which facilitates resetting of the excess flow valve without damage to the low pressure portion of an operational gas line. Still another object of this invention is to provide a gas line override valve which facilitates resetting of the excess flow valve without direct access to the flow valve.